List files downloaded during a browser session to track captured downloads. Provide a session ID to retrieve its download list.
List files captured from browser downloads for one session.
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | No | Target session id, from browser.create_session or browser.list_sessions. Optional when exactly one session is live; observe and act tools create one when none is. |
Changes observed during successful MCP inspections.
v1.8.1v1.4.2v1.0.3Input schema / additionalPropertiesAdded value: +falseInput schema / properties / session_id / maxLengthAdded value: +120Input schema / properties / session_id / minLengthAdded value: +1v0.5.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the 'captured from browser downloads' context and session scoping, but doesn't disclose details like whether the list includes file paths, sizes, or statuses, or whether it only lists files captured so far.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single, clear sentence that front-loads the action and resource. No wasted words; every part earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple read-only list tool with one optional parameter and full schema coverage, the description is mostly adequate. However, with no output schema, it doesn't hint at what the returned list contains (e.g., file names, paths, metadata), which an agent might need to know to decide whether to call read_download next.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100%, so the schema already documents the session_id parameter well, including its optionality and how to obtain it. The description adds no additional parameter semantics beyond what the schema provides, so baseline 3 is appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description states a specific verb ('List') and resource ('files captured from browser downloads') scoped to 'one session'. It clearly distinguishes from siblings like browser.list_sessions and browser.read_download, though it doesn't explicitly name them.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description implies usage for listing downloads within a session, and the schema clarifies the session_id is optional when exactly one session is live. However, it doesn't explicitly state when to prefer this over browser.read_download or how it relates to browser.list_sessions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.